Recently, a sensor capable of detecting the contact or approach of an object such as a finger has been put into practical use as a display device interface or the like. A capacitive touch panel, which is an example of the sensor, comprises an electrode to detect variation in electrostatic capacitance caused by the object. For example, a technology of forming a first sensor electrode and a second sensor electrode constituting the mutual-capacitive sensor of mesh-shaped thin metal wires has been known.